Stopper device for a receptacle neck, a receptacle fitted with such a device, and a method of fabricating such a device

ABSTRACT

The skirt ( 12 ) of this device is provided with a peripheral zone of weakness ( 16 ) that is broken on first opening of the device and on either side of which the skirt includes a first portion ( 14 ) suitable for being separated from the neck after the zone of weakness has broken, and a second portion ( 15 ) provided with a tongue ( 17 ) projecting from the inside face of the skirt towards the first skirt portion and adapted, at its free end ( 17 B), to come into abutment against an associated shoulder ( 8 ) on the neck ( 2 ) in order to retain the second skirt portion around the neck on first opening of the device. In order to guarantee stronger and more reliable retention of the second skirt portion, the tongue presents, in a longitudinal section plane of the skirt, a shape that is essentially curved, being convex towards the first skirt portion.

The present invention relates to a device for stoppering a receptacle neck and to a receptacle fitted with such a device, and it also relates to a method of fabricating such a device.

The invention relates more particularly to devices that include a skirt surrounding the neck of a receptacle and having a portion at the bottom, when the neck extends vertically with its rim pointing upwards, that is designed to remain around the neck after first opening of the device, while the remainder of the skirt, i.e. its top portion, is designed to be removable from the neck, while nevertheless initially being connected to the non-removable bottom portion of the skirt via a zone of weakness suitable for being broken on first opening of the device. This breakable zone serves as a mark of first use of the device for the attention of the consumer, while the non-removable skirt portion, in particular when it presents a substantial length, can be used for appearance purposes to cover the corresponding zone of the neck. In this light, the invention applies particularly but not exclusively to the field of packaging wines and spirits in glass bottles that traditionally have a neck covered in a long skirt with a non-removable bottom portion.

In order to retain the bottom skirt portion around the neck, it is known to cause an internal projection on said skirt portion to come into abutment with an associated swelling on the neck. When the skirt portion presents a length that is substantial, i.e. when it extends lengthwise downwards well beyond the above-mentioned swelling on the neck, it is common practice for the retaining projection to be provided in the form of a tongue that is molded integrally with the main portion of this skirt portion. One example of this type of skirt is shown diagrammatically in FIG. 7, where the skirt comprises a top portion 101 separated from its bottom portion 102 by a breakable line of weakness 103 represented merely by dashed lines. The bottom portion is provided with a tongue 104 of the type mentioned above that projects from the inside face of the portion 102 towards the top portion 101. On first opening of the stopper device including the skirt, the user entrains the top portion 101 upwards, as represented by arrow 105, thereby tending to break the line 103, while the tongue 104 tends to retain the bottom portion 102 around a receptacle neck 106, by coming into abutment against a transverse shoulder 107 on the neck.

Nevertheless, in practice, the skirt portion 102 is not always effectively retained by the tongue 104 since the tongue gives way by flipping over before the line 103 has broken completely. This is because of the stresses that are applied to the tongue as a result of the skirt portion 101 being entrained upwards 105, and/or because of dispersion in the dimensions of the various necks on which the skirt might be installed. Thus, as shown in FIG. 7, the tongue passes from its initial shape shown in continuous lines and of section that is substantially rectangular, to a curved shape with its convex side facing downwards, as shown in dashed lines, while the skirt portion 102 is entrained together with the portion 101 upwards relative to the neck 106. When it has this curved shape that is downwardly convex, the tongue no longer provides any vertical resistance against the shoulder 107, such that the shoulder continues to deform the tongue until it flips downwards into a position shown in chain-dotted lines in FIG. 7, with the connection zone between the tongue and the skirt portion 102 then forming a kind of flexible hinge without resistance.

The tendency of the tongue 104 to give way under the stresses generated on first opening of the device is encountered frequently when the skirt is made of a plastics material that, because of its relative structural flexibility, deforms radially outwards in the vicinity of the tongue, as represented by arrow 108. This problem is particularly marked when the skirt is obtained by molding, with the tongue 104 projecting downwards from the inside face of the skirt at the time of unmolding. Under such circumstances, prior to the stopper device including the skirt being put into place around the neck 106, it is necessary to fold the tongue 104 upwards so that it takes up its initial configuration shown in continuous lines in FIG. 7, which means that the connection zone between said tongue and the portion 102 must be deformed like a hinge. Thereafter, the tongue tends elastically more easily to give way on first opening of the device in order to return to the configuration it had on being unmolded, corresponding approximately to the configuration shown in chain-dotted lines.

Other examples of skirts provided internally with one or more retaining tongues are given in EP-A-0 410 059, U.S. Pat. No. 5,129,530, and U.S. Pat. No. 5,007,545. The tongues disclosed in those documents all present the shape of a segment of material coming from the inside face of the skirt and folded over at a sharp angle in the main portion thereof along a fold line that is orthogonal to the radius from the central longitudinal axis of the skirt. Thus, the segment is constituted by a base portion connected to the skirt via a flexible hinge zone, and by a free end portion connected to the base portion in hinged manner along the fold line. In practice, the annular fold line is made by appropriately shaping the tongue from a rectilinear configuration thereof, as obtained at the end of molding and analogous to the unmolding configuration shown in chain-dotted lines in FIG. 7.

On first opening of the stopper devices proposed in the three above-mentioned documents, the tongues deform by their free end portions folding towards their base portions along annular fold lines defined by the polygonal shapes of the sections of those tongues. As a result, only the free end portions of the tongues contribute effectively to retaining the skirt portion that is intended to remain permanently around the neck of the receptacle, with the risk that these end portions give way under the stresses by folding back completely against the base portions, while, by means of a lever effect around the angular fold lines, the base portions generate against the skirt outwardly directed stresses that are essentially radial at the flexible hinge zones (in a manner analogous to that represented by arrow 108 in FIG. 7). These local stresses are such that they can cause the plastics material constituting the skirt to be whitened locally in a manner that is visible from the outside of the skirt, thereby greatly deteriorating the appearance of the skirt, and making it unsuitable for use in the field of packaging wines and spirits where, in principle, the bottles need to be attractive.

The object of the present invention is to propose a stopper device with a tongue of the above-described type that guarantees strong and reliable retention of the skirt portion provided with the tongue, without degrading the outside appearance of said skirt portion.

To this end, the invention provides a device for stoppering a neck of a receptacle, as defined in claim 1.

With the device of the invention, and assuming that the longitudinal axis of the skirt extends vertically with the first portion of the skirt placed above the second portion, the or each tongue with its section of curved shape with its convex side facing upwards, guarantees considerable strength retaining the second portion of the skirt relative to the neck. When, on first opening of the device, the tongue comes into abutment axially against the associated swelling of the neck, the stress on the tongue is damped by its curved shape that tends to cause the tongue to flex so as to increase the curvature of its shape, thereby increasing its strength, until the zone of weakness between the two skirt portions breaks. In other words, on first opening of the device of the invention, the initial curved shape of the tongue obliges it to work in flexing, tending to increase the curvature of its shape. Since the tongue comes into abutment against the associated swelling of the neck at the free end of the tongue, opposite flexing movements, i.e. tending to decrease and then reverse the curvature of the section of the tongue, is made mechanically impossible. It will be understood that the curved shape that extends over the entire projecting width of the tongue towards the inside of the skirt in uniform manner, i.e. without any zone of curvature discontinuity from its free end to its end connected to the skirt, works with overall flexing movement, by modifying the overall curvature of the shape. In particular, the uniform dynamic behavior of the tongue means that it is not possible along the projecting width of the tongue to distinguish a free end portion from a base portion that present specific deformation behaviors that are different from each other.

This curved shape also presents the advantage of transmitting thrust forces to the portion of the skirt that is situated above the tongue, which portion can be thicker and stronger than that situated below the tongue. In particular, these thrust forces tend to stress the skirt with a radial component that is moderate or even negligible, thereby limiting the outward radial deformation of the skirt at the tongue, and thus reducing any risk of the plastics material whitening.

Other characteristics of the device that are advantageous taken individually or in any technically feasible combination are specified in dependent claims 2 to 12.

The invention also provides a receptacle including a neck fitted with a stopper device for the neck, as defined above.

The invention also provides a method of fabricating a device for stoppering a receptacle neck, as defined in claim 14.

The method of the invention thus makes it possible to obtain rapidly a skirt of plastics material that is ready for being put into place around the neck of the receptacle. The various operations of the method, such as molding the skirt and folding back the tongue, can be implemented using movements that are substantially axial, such that, in practice, the method can be automated without degrading the quality with which it is performed.

An advantageous characteristic of the method is specified in claim 15.

The invention can be better understood on reading the following description given purely by way of example and made with reference to the accompanying drawings, in which:

FIG. 1 is a longitudinal section of a stopper device of the invention, shown around a receptacle neck, the right-hand half of the figure shows the device in its assembled configuration on the neck and actually in place around the neck, while the left-hand half shows the device in a state prior to reaching the configuration shown in the right-hand half;

FIG. 2 is a view on a larger scale showing the circled detail II of FIG. 1;

FIG. 3 is a view analogous to FIG. 1 showing a variant of the stopper device of the invention, shown fitted around a receptacle neck and prior to first opening;

FIG. 4 is a perspective view of an outer capsule of the FIG. 3 device, before being assembled with the other components of the device;

FIG. 5 is a fragmentary longitudinal section of the FIG. 4 capsule;

FIG. 6 is a view analogous to FIG. 4 showing another variant of the capsule of a device of the invention; and

FIG. 7 is a view analogous to FIG. 2 showing an example from the prior art, as described above.

FIGS. 1 and 2 show a stopper device 1 adapted to be releasably screwed onto a neck 2 of a receptacle 3, e.g. a bottle made of glass or the like, for containing an alcoholic beverage, and in particular wine. The neck presents a shape that is generally tubular about a longitudinal axis X-X.

For convenience, in the description below, it is assumed that terms such as “top” and “up” correspond to a direction generally parallel to the axis X-X going from the body of the receptacle 3 towards its neck 2, i.e. in the direction that is upwards in FIGS. 1 and 2, whereas the terms “bottom” and “down” correspond to the opposite direction. The same conventions are used with respect to FIGS. 3 to 6.

At its top end, the neck 2 defines a rim 4 over which the liquid contained in the receptacle 3 is to be poured out. The outside face of the neck is provided in succession going downwards, with a helical thread 5 and with a ring 6, both projecting radially outwards. At the transition between the bottom end of the ring and the remainder of the neck, which forms an elongate portion 7 having a frustoconical outside face about the axis X-X that diverges downwards, there is formed a transverse shoulder 8 that slopes upwards a little on going away from the axis X-X and relative to a plane perpendicular to said axis.

The stopper device 1 comprises three distinct parts, namely an outer capsule 10, an insert 20, and an optional sealing disk 30, which parts are designed to be assembled coaxially with one another and then mounted together on the neck 2.

The capsule 10 and the insert 20 are both generally tubular in shape about a longitudinal axis that coincides substantially with the axis X-X when the device 1 is assembled and fitted on the neck 2, as shown in the figures. Both the capsule and the insert are open at their bottom ends and closed at their top ends by respective end walls 11 and 21, each having a tubular skirt 12, 22 centered about the axis X-X extending axially downwards from its periphery.

The insert 20 is adapted to be inserted inside the capsule 10 and to be held stationary therein permanently, both axially and in rotation about the axis X-X. These two parts then form a one-piece stopper 40 with the wall 11 and the skirt 12 covering the outside faces of the wall 21 and of the skirt 22. The insert can be held stationary inside the capsule by heat-sealing, in particular using ultrasound, by adhesive, or by having complementary shapes between the walls 11, 12, 21, and 22, as described in detail in the French patent application filed in the name of the present Applicant and recorded under the number 04/03154.

The sealing disk 30 is housed inside the insert 20 against the end wall 21, optionally with an interposed layer of adhesive. Advantageously, the insert is provided with lips 23 projecting radially inwards from the top portion of the skirt 22, these lips serving to hold the disk axially downwards in order to prevent it from subsequently escaping from the inside of the insert. Details of how these lips can be made are given in the above-mentioned French patent application No. 04/03154.

The bottom portion of the inside face of the skirt 22 is provided with a thread 24 projecting radially inwards and complementary to the outside thread 5 on the neck 2, such that the stopper 40 is suitable for being screwed on and off the neck. To make the stopper easier to hold, the bottom portion of the outside face of the skirt 12 is advantageously provided with longitudinal grooves 13.

The skirt 12 is longer than the skirt 22, such that in the assembled state of the device 1, the bottom of the skirt 12 extends a long way below the axial level of the bottom end edge 25 of the insert 20, so as to cover the neck 2 from its rim 4 and including its elongate portion 7.

When the device 1 is opened for the first time, the skirt 12 is adapted to separate into two distinct portions of approximately the same length, i.e. a top portion 14 formed integrally with the end wall 11, and a bottom portion 15 initially connected to the top portion 14 by a line of weakness 16 represented diagrammatically by dashed lines in FIGS. 1 and 2. This line 16 is provided in the main portion of the skirt 12 a little below the level of the bottom end edge 25 of the insert 20 going along the axis X-X, such that the top portion 14 of the skirt alone houses all of the insert 20 when the device 1 is assembled.

In practice, the line of weakness 16 is constituted for example by breakable bridges or by a plurality of circumferential cuts or notches formed through the wall of the skirt 12.

In order to separate the portions 14 and 15 of the skirt by breaking the line 16 when the device 1 is opened for the first time, the bottom portion 15 is held axially relative to the neck 2 by a tongue 17 formed integrally with the main portion of said bottom portion 15 and projecting from the inside face thereof. Towards the axis X-X, the tongue extends upwards when the device 1 is in its assembled configuration on the neck 2, as shown in the right-hand portion of FIG. 1, whereas when the device is in its prior configuration as shown in the left-hand portion of FIG. 1, the tongue extends downwards.

The thickness of the tongue 17, i.e. its smallest dimension in the plane of FIGS. 1 and 2, is substantially constant along its other dimension that corresponds to the width over which it projects inwards from the inside face of the skirt portion 15, i.e. beyond its end 17A connected to the skirt wall 15 and its free end 17B. In section radially relative to the axis X-X, i.e. in the plane of FIGS. 1 and 2, the tongue 17 does not present a section of rectangular shape, but rather of curved shape being upwardly convex. As a result, in this plane, the tongue 17 presents an arcuate profile, corresponding approximately to one-eighth of a circle, it being observed that the curvature of the tongue 17 is oriented towards the axis X-X and downwards in FIG. 1, i.e. towards the body of the receptacle 3. It is emphasized that FIGS. 1 and 2, and also FIGS. 3 to 6 described below and showing clearly the curved shape of the invention, are diagrammatic figures concerning the precise dimensions of the tongue. Where appropriate, the person skilled in the art can refer to the details given in the present text for quantifying the relative dimensions of the tongue.

In other words, the top face of the tongue 17 is essentially convex, while its bottom face is essentially concave. More precisely, the free end 17B and the main portion 17C of the tongue present, on one side, respective top faces that are convex, and, on the opposite side, respective bottom faces that are concave, while the end 17A of the tongue presents opposite faces that change their direction of curvature because they are connected to the skirt portion 15.

The dimensions of the tongue 17 and its axial position along the skirt portion 15 are designed so that when the device 1 is in the assembly configuration and said device is fitted around the neck 2, the end 17B of the tongue is situated level with the shoulder 8. In practice, depending on the exact dimensions of the neck 2, in particular concerning its ring 6 and its shoulder 8, and depending on the dimensions of the device 1, the end 17B of the tongue is situated immediately beneath the shoulder 8, being merely in contact with the shoulder, ignoring any functional clearance.

The capsule 10 is made of a semirigid plastics material, such as polypropylene or polyethylene, polyethylene being preferred, in particular for reasons of appearance. The capsule 10 is obtained by molding the plastics material, so as to form the end wall 11 and the skirt 12 simultaneously, in particular together with the molded tongue 17 having its curved shape. The capsule is made easier to unmold by providing for the tongue to extend, on leaving the mold, in its state as shown in FIG. 1, i.e. with its free end 17B pointing downwards.

Before or after inserting the disk 30 inside the insert 20, assembling the stopper device 1 consists in placing the insert inside the skirt 12 of the capsule 10 in its above-described state on leaving the mold, by introducing the insert axially and forcing it in from the open bottom end of the capsule. The tooling for performing this insertion then advantageously ensures that the tongue 17 is folded upwards so as to go into its state shown in the right-hand portion of FIG. 1. The device 1 is then in its configuration for assembly to the neck 2.

The stopper 40 made up of the insert 20 held stationary in the capsule 10, is then fitted onto the neck 20 by screw fastening so that firstly the tongue 17 passes under the shoulder 8 on the neck, and secondly the sealing disk 30 is compressed axially between the rim 4 and the end wall 21 of the insert, the bottom face of the disk advantageously defining a hollow annular indentation 31 complementary to the rim. The skirt 12 then covers the neck including its elongate portion 7.

To open the device 1, the user unscrews the stopper 40, i.e. turns it about the axis X-X by gripping it via the grooves 13. On the first occasion the device is opened, the upward movement of the stopper resulting from being unscrewed, and as represented by arrows 50 in FIG. 2, causes the two portions 14 and 15 of the skirt to separate by breaking the line of weakness 16. While the top portion 14 is being driven upwards, the bottom portion 15 is retained axially by its tongue 17 coming into axial abutment against the shoulder 8 of the neck 2. Under the effect of the upward movement, the upwardly convex shape of the section of the tongue gives rise to the tongue flexing so that its curvature increases, the tongue thus passing from its initial curved configuration as shown in continuous lines in FIG. 2, to a configuration in which it is flexed to a greater extent, as shown in dashed lines in that figure. At the end 17B of the tongue, in order to obtain the corresponding flexing of the tongue that is directed outwards and upwards, as represented by arrow 51, it is necessary to apply an axial force that is sufficient to break the line 16. In other words, this flexing serves to accommodate the force needed to retain the bottom portions 15 of the skirt relative to the shoulder 8 until the line 16 breaks.

It will be understood that the curved shape of the tongue gives rise to overall flexing of the tongue, with the tongue being stressed in bending in a manner that is uniform over its entire projecting width. The uniformity of the dynamic behavior of the tongue is emphasized by the continuous arcuate profile of its curved shape. In practice, curvature discontinuities are to be avoided in the tongue: variations restricted to ±15% about a mean value of curvature along the projecting width of the tongue, are preferred.

Similarly, it will be understood that the constant thickness of the tongue contributes to obtaining the effect of dynamic uniformity. In practice, variations restricted to ±10% about a mean thickness value along the projecting width of the tongue, are preferred.

Since the tongue 17 presents curvature oriented towards the axis X-X and downwards, the increased flexing of the tongue while the skirt 12 is moving upwards prior to the line 16 breaking, also tends advantageously to make its curvature more uniform across its projecting width between its end 17B and its main portion 17C.

In addition, the thrust forces transmitted to the skirt 12 are transmitted mainly via the region 15A of the bottom portion 15 situated between the line of weakness 16 and the tongue 17, i.e. the region situated under the tongue 17 in the configuration of FIGS. 1 and 2 which corresponds to the normal utilization configuration of the receptacle 3.

FIGS. 3 to 5 show a variant 100 of the stopper device 1 of FIGS. 1 and 2 fitted around the neck 2 of the receptacle 3. For convenience, components common to the devices 1 and 100 are given the same numerical references. The device 100 differs from the device 1 essentially by the structure of its means for retaining the skirt portion 15: instead of having a single tongue like the tongue 17 extending continuously around the entire inside periphery of this skirt portion, the skirt 12 of the device 100 is provided with a plurality of paddles 171 formed integrally with a band 172 that is common to all of the paddles, this band itself being formed integrally with the main portion of the skirt portion 15. The band 172 projects towards the axis X-X from the inside face 12A of the skirt 12 from the portion 15, running continuously around the entire inside periphery of the skirt, as can be seen in FIGS. 4 and 5.

The paddles 171 are identical to one another. Each paddle extends towards the axis X-X by projecting from the band 172. For structural reasons, these paddles are advantageously distributed in substantially uniform manner around the inside periphery of the band. The band 172 thus connects each of the paddles to the inside face 12A of the skirt 12 via the skirt portion 15, while leaving empty spaces 173 between successive pairs of paddles going around the periphery of the band. Each band portion 172 from which one of the paddles 171 extends and the associated paddle together form a tongue 170 for retaining the skirt portion 15, that is functionally analogous to a portion of the tongue 17 shown in FIGS. 1 and 2.

The thickness e₁₇₂ of the band 172, i.e. its smallest dimension in the plane of FIGS. 3 and 5, is substantially constant along its other two dimensions, in particular in the above-mentioned plane, between its end 172A connected to the skirt portion 15 and its end 172B that is either connected to one of the paddles 171 or else free in one of the intermediate spaces 173. The thickness e₁₇₁ of each paddle is likewise constant, in particular between its end 171A connected to the inside end 172B of the band, and its free end 171B. Amongst other reasons, the thicknesses e₁₇₁ and e₁₇₂ are substantially equal in order to facilitate molding and unmolding the band and the paddles together with the remainder of the skirt 12.

Between its inner and outer ends 172A and 172B, the band 172 presents a width l₁₇₂ projecting towards the inside from the inside face 12A of the skirt 12 that is less than the dimension l₁₇₁ of, each paddle 171 between its inner and outer ends 171A and 171B, i.e. the inwardly projecting width of said paddle from the end 172B of the band.

The band 172 and each paddle 171 extend continuously, prolonging each other towards the axis X-X in the plane of FIGS. 3 and 5. In the configuration of FIG. 3, which corresponds to an assembly configuration on the neck 2, the band and the paddles extend upwards towards the axis X-X, while in the prior configuration as shown in FIGS. 4 and 5, which corresponds to a molding configuration, the band and the paddles extend downwards, for the same reasons as those given above for the device 1. In both configurations, each of the paddles, together with the associated portion of band, i.e. each of the tongues 170, presents in the plane of FIGS. 3 and 5 an overall section that is curved in shape, being upwardly convex. In the example shown, each tongue 170 presents an arcuate profile, corresponding approximately to one-eighth of a circle. As a result, the band and the paddles guarantee high strength for retaining the skirt portion 15 relative to the neck 2 on first opening of the device 1, their curved profile constraining them to work over their entire projecting width with general flexing movement, tending to further increase the curvature of the profile, as explained above for the device 1.

The stopper device 100 is assembled in a manner analogous to the device 1, and in particular the band 172 and the paddles 171 are driven upwards so that the tongues 170 pass into their assembly configuration as shown in FIG. 3. While the band and the paddles are being driven upwards, significant stresses are applied to the band and to the paddles so as to cause them to be deformed plastically like a hinge at the end 172A of the band that is connected to the skirt portion 15, as represented by arrow 172C in FIG. 5. Non-negligible stresses are also applied to the zone of material connecting together the band and the wall of the skirt 12 while the skirt is being unmolded. All of these stresses present a magnitude that is greater in register with the paddles 171 than in register with the empty spaces 173, because of the structural resistance delivered by the paddles. Nevertheless, to avoid excessive levels of stress within the paddles, and above all within the band portions connecting each of said paddles, in radial section, to the skirt, the band serves to distribute these stresses, in particular within the remaining portions of the band, i.e. within its portions projecting radially towards an empty space 173, in radial section. This limits the risk of the zones of plastics material that are stressed in this way, and in particular the outside surface zone of the skirt portion 15 level with the end 172A of the band, becoming spoilt by stress that is excessive, and in particular being whitened.

Since the band 172 extends continuously around the entire inside periphery of the skirt 12, the stresses within the plastics material are distributed in substantially uniform manner over the entire peripheral outline of the band, even if the resultant of the flexing drive applied to the band is slightly offset relative to the axis X-X.

In the example shown in the figures, the projecting width l₁₇₂ of the band is less than the projecting width l₁₇₁ of the paddles. Nevertheless, in practice, depending on the stress levels expected during unmolding the skirt and when folding back the paddles, the ratio between these widths can be adjusted.

The device 100 is opened in manner analogous to that of the device 1, in particular concerning the overall flexing work of the tongues 170.

Naturally, it is possible to envisage modifications and variants to the above-described stopper devices 1 and 100, and also to their method of manufacture. As examples:

-   -   unlike the example of FIGS. 1 and 2, in which the tongue 17         extends continuously around the entire inside periphery of the         skirt portion 15, a variant 200 of the device 1 as shown in FIG.         6 consists in causing the tongue to extend in discontinuous         manner around its periphery, which amounts to obtaining a         plurality of distinct individual tongues 270 that are         advantageously uniformly distributed around the inside periphery         of the skirt 12; each tongue 270 is thus functionally analogous         to a portion of the tongue 17 or to one of the tongues 170, it         being observed that unlike those tongues, each of the tongues         270 extends from its end 270A connected to the inside face of         the skirt to its free end 270B, but without being connected to         one another by a common peripheral band or the like, such as the         band 171;     -   on first opening of the stopper device, to limit the risks of         the or each tongue 17, 170, 270 becoming radially jammed         vertically between the ring 6 on the neck 2 and the skirt         portion 15, in particular if the ring 6 turns out to be of         smaller diameter than intended because of large dispersion in         the dimensions of necks in a given batch, the skirt 12 is         provided internally with a plurality of projections 19         projecting radially from the inside face of the skirt portion 15         and distributed substantially uniformly around the inside         periphery of this skirt portion; with multiple tongues 170 or         270, each projection 19 is situated around the periphery of the         skirt in register with one of the tongues; along the axis X-X,         each projection is situated between the line of weakness 16 and         the end 17A, 172A, 270A of the tongue connected to the skirt,         being disposed substantially at the height of the free end 17B,         171B, 270B of the tongue when pressed against the inside face of         the skirt, with its free end pointing upwards; as a result, the         free end 17B, 171B, 270B of the or each tongue 17, 170, 270 is         held radially away from the inside face of the skirt 12 by the         interposed projection 19, thereby improving the reliability with         which said free end is put into axial abutment against the         shoulder 8 of the ring on the neck during first opening of the         device, in particular given the curved configuration of the         tongue that is convex towards the projection 19, so that, where         appropriate, the tongue can interfere with the projection         quickly on first opening; this disposition is more effective         than providing extra thickness at the free end of the tongue,         and it also makes molding and unmolding the capsule easier;     -   the tongue 17 or the tongues 170 or 270 can be folded from their         state on leaving the mold to their state associated with the         configuration for assembling the device on the neck by using         tooling that is specific and independent of the tooling used for         placing the insert 20 in the capsule 10;     -   instead of providing the stopper 40 in two distinct portions for         being assembled permanently to each other, the stopper could be         made as a single piece with a skirt presenting a line of         weakness and one or more tongues analogous to the line 16 and to         the tongue 17 of the device 1 or to the tongues 170 or 270 of         the device 100 or 200; and/or     -   the bottom portion 15 of the skirt 12 may extend over a short         distance downwards in FIGS. 1 and 3 below the tongue 17 or the         tongues 170, 270; the portion 15 may even be interrupted         immediately beneath said tongue(s); in other words, the region         15B could be very short or even non-existent. 

1. A device for stoppering a neck of a receptacle, the device comprising an elongate skirt of plastics material for surrounding the neck and provided with a peripheral zone of weakness that is adapted to break on first opening of the device and on either side of which, along the longitudinal axis of the skirt, the skirt includes a first skirt portion suitable for being separated from the neck after the zone of weakness has broken and a second skirt portion provided with at least one tongue that, in an assembly configuration for assembling the device on the neck, projects from the inside face of the skirt towards the first skirt portion and is adapted, at its free end, to come into abutment axially against an associated swelling on the neck in order to retain the second skirt portion around the neck on first opening of the device, wherein, in the assembly configuration for the device on the neck, the or each tongue presents, in a longitudinal section plane of the skirt, a shape that is essentially curved, being convex towards the first skirt portion.
 2. A device according to claim 1, wherein the essentially curved shape of the or each tongue presents, in the longitudinal section plane of the skirt, a profile that is arcuate.
 3. A device according to claim 2, wherein said arcuate profile corresponds approximately to one-eighth of a circle.
 4. A device according to claim 1, wherein the essentially curved shape of the each tongue presents substantially constant curvature along its width projecting from the inside face of the skirt.
 5. A device according to claim 4, wherein the variations of said curvature along the projecting width of the or each tongue are restricted to within ±15% of a mean value of curvature.
 6. A device according to claim 1, wherein the or each tongue presents, in the longitudinal section plane of the skirt, thickness that is substantially constant.
 7. A device according to claim 6, wherein the variations in said thickness along the projecting width of the or each tongue from the inside face of the skirt are restricted to within ±10% of a mean thickness value.
 8. A device according to claim 1, wherein, on first opening of the device, the or each tongue is adapted to flex between two extreme configurations, in each of which the tongue conserves, in a longitudinal section plane of the skirt, its essentially curved shape that is convex towards the first skirt portion.
 9. A device according to claim 1, wherein the or each tongue is formed integrally with the inside face of the skirt and is suitable for passing, relative to the skirt, from a molding configuration in which the tongue is molded together with the remainder of the skirt, to the assembly configuration for assembling the device on the neck, which assembly configuration is different from the molding configuration.
 10. A device according to claim 1, wherein a single tongue is provided that extends over the entire inside periphery of the second skirt portion.
 11. A device according to claim 1, wherein a plurality of individual tongues are provided discontinuously around the inside periphery of the second skirt portion, these individual tongues being advantageously distributed in substantially uniform manner around said periphery.
 12. A device according to claim 1, wherein the second skirt portion is provided internally with at least one projection for being interposed radially between said skirt portion and the free end of the or each tongue in the assembly configuration.
 13. A receptacle including a neck and fitted with a device for stoppering the neck, the device being in accordance with claim
 1. 14. A method of fabricating a device for stoppering a receptacle neck, in which: a plastics material is molded to form an elongate skirt for surrounding the neck, which skirt is provided with a peripheral zone of weakness that is adapted to be broken on first opening of the device and on either side of which, along the longitudinal axis of the skirt, the skirt includes a first skirt portion suitable for being separated from the neck after the zone of weakness has broken, and a second skirt portion provided with at least one tongue that, on leaving the mold, projects from the inside face of the skirt away from the first portion of the skirt; and then the or each tongue is folded towards the first skirt portion until the tongue extends from the inside face of the skirt towards said first skirt portion, the tongue then being adapted at its free end to come axially into abutment against an associated swelling on the neck so as to retain the second skirt portion around the neck on first opening of the device; wherein, during molding of the skirt, the or each tongue is molded in such a manner as to present, in a longitudinal section plane of the skirt, a shape that is essentially curved, being convex towards the first skirt portion.
 15. A method according to claim 14, wherein an insert suitable for being secured to the inside of the skirt is used to form at least a portion of the stopper device, and in that the or each tongue is folded during insertion of said insert into the skirt. 